Fender single coil pickups:

1. If the beginning magnet wire is still extended from the beginning of the coil you can splice an extension by carefully soldering a new chemically stripped magnet wire to the existing piece.
2. If the beginning magnet wire is not extended from the beginning of the coil, then connecting a new beginning wire will be difficult or impossible.
3. If the finish magnet wire is broken before the eyelet, then it’s possible to unwrap a turn to give enough length to wrap through the clean eyelet and resolder.
4. If the finish magnet wire is not available and is broken somewhere in the outer part of the coil, than again you need to use a fine tooth brush to gently unwrap the outer turns to find the break. At times, single coil pickups need to have the wax removed as it’s hard and difficult to remove turns without breaking the wire again.